What is an acid?

When talking about the term acid, it refers to a molecule or ion capable of either donating a proton (hydrogen ion H+), called a bronsted-lowry acid, or forming a covalent bond with the electron pair, called a Lewis acid. 

An acid can be described as any liquid-based solution which tastes sour and may dissolve substances in it. It may also burn skin and clothes. Acid changes blue litmus paper to red. The acid reacts with some metals to give out hydrogen and some bases to form salts. It also promotes chemical reactions.

What are some examples of acid?

Examples of acid may include inorganic substances, called the mineral acids – sulphuric acid, nitric acid, hydrochloric acid, and phosphoric acid – and the organic compounds belonging to the carboxylic acid sulfonic acid, and phenol groups. 

What are the different types of acids?

There are two types of acids, and these are:

  • Organic Acids:Organic acids are generally obtained from natural sources and they are weak in comparison to inorganic acids.Organic acids and their derivatives cover a wide array of substances. Because of the variety of chemical structures offered by the organic acids, these are used to manufacture almost every type of chemical. Examples of organic acids are acetic acid, citric acid, formic acid, etc.
  • Inorganic Acids: Inorganic acids, also known as mineral acids, the anhydrous form of such acids can be solid or gaseous.Inorganic acids are toxic and corrosive. Inorganic acids are capable of burning the skin. The acids falling under inorganic acids are procured from minerals, and these do not contain carbon. Some examples of inorganic acids are sulphuric acid, nitric acid, phosphoric acid, etc.

Apart from the acids mentioned above, the acids are also classified into different types according to a different basis. Here are more acid types: oxy-acid, hydracid, strong and weak acids, concentrated acids, diluted acids, etc.

What is the basicity of an acid?

The number of replaceable hydrogen atoms present in the molecule of an acid can be defined as the basicity of acid. 

There are three types of basicity of acid, and these are:

  • Monobasic acid: The molecule of an acid that contains one replaceable hydrogen atom is called monobasic acid, and its basicity is 1.
  • Dibasic acid: The molecule of an acid that contains two replaceable hydrogen atoms is called dibasic atoms, and its basicity is 2.
  • Tribasic Acid: The molecule of an acid that contains three replaceable hydrogen atoms is referred to as tribasic atoms, and its basicity is 3.

Mentioning the examples of the basicity of an acid:

Following mentioned are some examples of the basicity of an acid:

  • The basicity of the acid H2SO4 is 2.
  • The basicity of the acid H3PO4 is 3.
  • The basicity of the acid HNO3 is 1.

Acetic Acid

Acetic acid is a byproduct of fermentation and gives vinegar its odour. Vinegar is about 4-6% acetic acid in water. Acetic acid is also known as vinegar, ethylic, ethanoic, and methane carboxylic acid. The formula of acetic acid is CH3COOH. 

The basicity of acetic acid:

CH3COOH + NaOH →CH3COONa + H2O

As it gives only one hydrogen ion, the basicity of acetic acid is 1. 

Orthophosphoric Acid

Orthophosphoric acid is also known as Phosphoric acid, a triprotic acid. This acid exists as a dense liquid and acts as an irritant or corrosive to both human’s and animals’ eyes, skin, and other mucus membranes. However, its salts show a lower irritancy potential. The formula of this acid is H3PO4. 

The basicity of orthophosphoric acid is 3.  

How to find the basicity of an acid?

The basicity of acid is the number of hydrogen atoms produced by the molecule of an acid when it gets ionized in the aqueous medium.

To know better about how to find the basicity of acid, let’s take the following mentioned examples:

  • HCl

HCl is split into H+ + Cl-

In the aqueous medium,

HCl + H20 → H3O+ +Cl-

Here hydronium ions can also be referred to as the H+ ions because they can break into water and H+ ion.

H3O+ ⇋ H20 + H+

Here, the number of hydrogen (hydronium H3O+) ions produces equals 1.

Therefore, it can be said that the basicity of HCl is equal to 1.

Similarly, 

  • There are two replaceable hydrogen atoms present in sulphuric acid (H2SO4), which means the basicity of sulphuric acid is 2.
  • In phosphoric acid (H3PO4), there are three replaceable hydrogen atoms which mean the basicity of the phosphoric acid is 3.

Conclusion

Acids are a very harmful substance as it causes damage to humans and animals in various ways. It should be handled with the utmost care, and precautions should be taken while working with it in laboratories and factories. It is very important to know the characteristics and nature of the acid with which one is working and take precautionary steps accordingly.